Microtome

ABSTRACT

The present invention relates to a microtome ( 1 ) having functional regions to be operated manually, in particular a sample holder ( 2 ), a cutting device ( 3 ), a section removal system ( 4 ), and a section collection pan ( 5 ). A microtome ( 1 ) is described in which the particularly firm contact or adhesion of sectioning waste fragments and, in particular, of thin sections can be at least largely avoided. For this purpose, the microtome ( 1 ) according to the present invention is characterized in that the components of the microtome ( 1 ) that can be brought into contact with paraffin sections are embodied in electrically conductive fashion.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority of German utility model application 202006 005 259.3 filed Mar. 30, 2006 and German utility model application20 2006 008 329.4 filed May 26, 2006, which are both incorporated byreference herein.

FIELD OF THE INVENTION

The present invention relates to a microtome having functional regionsto be operated manually, in particular a sample holder, a cuttingdevice, a section removal system, and a section collection pan.

BACKGROUND OF THE INVENTION

Microtomes of this kind are known from the existing art, for examplefrom DE 103 52 578 B3, and are used predominantly for the production ofthin paraffin sections in the fields of biology, medicine, andindustrial research. The samples and preparations to be investigated areusually embedded in paraffin, in a preceding preparation process, into aspecimen holding device, for example a carrier basket. A drive devicethat, by means of a relative motion, guides the sample, located in thespecimen holding device, over a knife arranged on the microtome isprovided for sectioning. The knife is generally horizontallydisplaceable in a knife holding device, and can be clamped in at anadjustable angle in defined fashion.

In so-called rotary microtomes, the drive device implements both themovement of the knife holding device in adjustable micrometer steps(referred to as horizontal advance) and the vertical sectioning motion,which is usually generated by a crank mechanism driven by a handwheel.

A trimming function can be provided in order to produce an optimumsection surface. For this, the knife holding device can be manuallydirected onto the vertically movable specimen holding apparatus forfirst sectioning operations, via a trimming lever, in steps that arelarge as compared with the actual section thickness. Unusable sectioningwaste occurs in this operation, and accumulates in a section collectionpan of the microtome.

The samples to be investigated are often contaminated or bacteriallyinfected biological material with which paraffin from the preparationprocess can be mixed. Even during ordinary sectioning of the sampleswith the microtome, fine sectioning waste unavoidably occurs; this dropsdown from the microtome knife and becomes deposited on portions of themicrotome located therebelow, for example portions of its housing, inparticular also in open gaps and especially in the section collectionpan.

Because of the very complicated motion sequence, a complex mechanism isnecessary on and in the microtome. Openings into the interior of themicrotome, which are often covered with movable sliders, unavoidablyremain at movement interfaces. Small slits, gaps, and openings in themicrotome housing likewise occur, as a consequence of manufacture, inthe vicinity of the aforesaid functional regions.

To prevent infection due to the contaminated sectioning waste, operatingpersonnel are forced to intensively clean and disinfect the microtomeand, in particular, the operating elements of the functional regions atrelative short time intervals.

The section collection pan is particularly affected, since both thesectioning waste from trimming sections and the thin sections ofcontaminated samples that drop down build up in it. Large adheringsectioning waste fragments that are firmly in contact with the surfacebecause of adhesion present a particular cleaning problem.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to solve theproblems recited above and, in particular, to describe and furtherdevelop a microtome of the aforesaid kind in which firm contact oradhesion of sectioning waste fragments, and in particular of thinsections, can be at least largely avoided.

The microtome according to the present invention of the generic typeachieves the aforesaid object by way of the features of Claim 1.According thereto, a microtome of this kind is characterized in that thecomponents of the microtome that can be brought into contact withparaffin sections are embodied in electrically conductive fashion. Thecorresponding components should be embodied in such a way that theirelectrical conductivity remains substantially unchanged over time, i.e.ideally is permanently guaranteed.

What has been recognized according to the present invention is firstlythat thin sections of contaminated samples, especially those droppingdown, adhere very particularly firmly to housing portions of themicrotome, and in particular to the section collection pan, if thehousing portions of the microtome and/or the section collection pan areelectrostatically charged. It is therefore proposed, in accordance withthe present invention, that the components of the microtome that usuallycome into contact with paraffin sections and/or with sectioning waste beembodied in electrically conductive fashion. Ideally, therefore, allcomponents that come into contact with paraffin sections and/or withsectioning waste are embodied in electrically conductive fashion. Itcould also be sufficient, however, to embody in electrically conductivefashion substantially and only the components of the microtome that mostprobably or most frequently come into contact with paraffin sectionsand/or with sectioning waste. By the fact that the relevant componentsare embodied in electrically conductive fashion, they should all be at acommon electrical potential, and electrostatic charging of individualcomponents of the microtome should accordingly be effectively avoided.It is thereby possible to decrease the possibility that, in particular,thin sections, paraffin sections, and/or sectioning waste becomespermanently or particularly firmly deposited onto individual componentsof the microtome because of electrostatic charging of the individualcomponents, and can be removed again with difficulty or only withtime-consuming cleaning efforts.

In particularly preferred fashion, therefore, housing portions of themicrotome are embodied in electrically conductive fashion. Inparticular, housing portions of the cutting device, of the sectionremoval system, and/or of the section collection pan could be embodiedin electrically conductive fashion. Thus in addition to the internalcomponents of the microtome, its housing portions can thereforeadditionally be embodied in electrically conductive fashion.

Very particularly preferably, the housing portions that on conventionalmicrotomes are usually embodied from plastic are embodied inelectrically conductive fashion. This refers in particular to thesection collection pan, which hitherto has been fabricated in somecircumstances from plastic and has had a coating containing silver ionsand having an antimicrobial effect. Over time, however, a coating ofthis kind, which in some circumstances can likewise act in electricallyantistatic fashion, can sooner or later be removed. The housing portionsusually embodied from plastic can either be replaced by housing portionsmade of metal, or can be constituted by electrically conductive housingportions.

In a preferred embodiment, the housing portions of the microtome couldthus comprise electrically conductive plastic. This could beimplemented, in particular, in that the corresponding housing portionsmade of plastic comprise electrically conductive additions. Appropriatein this context, for example, are additions that could respectivelycomprise a metal mat, a steel fiber braid, a metal lattice, metalfibers, and/or a (permanent) metallic coating.

Very particularly preferably, at least one housing portion couldcomprise a plastic having the designation “Grilon BS EC.” This plasticis a standard-viscosity, more heat-stabilized injection-molding PA6grade having stainless steel fibers, this plastic exhibiting electricalconductivity or electrical antistatic properties in particular becauseof the stainless steel fibers. This plastic moreover exhibitsthermoplastic properties with good impact toughness, and can be madelight in color. This plastic is offered commercially, for example, byEMS Grivory or EMS-CHEMIE GmbH, Warthweg 14, 64823 Gross-Umstadt,Germany. Alternatively or additionally, at least one housing portioncould be a plastic having the designation Antistatic-Equipped “GrilamidLKN-5H,” of the same manufacturing company. Grilamid LKN-5H is aheat-stabilized polyamide-12 reinforced with 50% glass spheres. Theproperties of this injection-molding grade are: low water uptake,extremely dimensionally accurate, dimensionally stable, very littleshrinkage, good sliding properties, and high abrasion strength.

The section collection pan could be embodied from (electricallyconductive) metal, in particular stainless steel. Electricalconductivity would thereby exist for the section collection pan evenwithout a coating.

In particularly preferred fashion, the microtome is embodied inantistatic fashion or comprises an antistatically embodied knife holder.This could be achieved, for example, in that at least one means withwhich the electrically conductively embodied components of the microtomeare electrically connectable to one another is provided. The componentselectrically connected to one another can thereby be brought to a commonelectrical potential or grounded. Concretely, the means could comprisean electrically conductive cable.

The microtome according to the present invention could be embodied inthe form of a rotary microtome or a sliding microtome or a rotating discmicrotome.

BRIEF DESCRIPTION OF THE DRAWINGS

There are various ways of advantageously embodying and refining theteaching of the present invention. The reader is referred, for thatpurpose, on the one hand to the claims subordinate to Claim 1, and onthe other hand to the explanation below of the preferred exemplifyingembodiments of the invention with reference to the drawings. Inconjunction with the explanation of the preferred exemplifyingembodiments of the invention with reference to the drawings, anexplanation is also given of generally preferred embodiments andrefinements of the teaching. In the drawings:

FIG. 1 is a schematic depiction of an exemplifying embodiment of amicrotome according to the present invention; and

FIG. 2 is a schematic depiction of a section collection pan of themicrotome of FIG. 1.

In the Figures, identical or similar assemblies are labeled with thesame reference characters. The microtome is described and furtherexplained below with reference to an exemplifying embodiment depictedschematically in the drawings.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a rotary microtome 1 having functional regions to beoperated manually, namely sample holder 2, cutting device 3, and sectionremoval system 4. The sectioned material (not shown) dropping down fromsection removal system 4 is accumulated in a section collection pan 5.The up-and-down motion of sample holder 2, and the shifting of cuttingdevice 3, are controlled by actuation of a hand crank 6 via a linkage(not further depicted).

The functional units are constructed from a plurality of structuralelements. A clamping lever 7 is provided for rapid exchange of a samplecarrier (not shown). Microtome knife 8 can also be aligned andimmobilized in a pivotable knife receptacle by way of clamping shafts 9,10. Cutting device 3 is mounted on concealed guidance rails.

Poorly accessible cavities and narrow slits and gaps, in whichcontaminated sectioned material can become deposited, are created forstructural reasons when the numerous structural elements are fittedtogether. Contaminated material can also be transferred to hand crank 6or to clamping lever 7 as a result of manipulation of the sample infunctional regions 2, 3, 4, 5. These functional regions in particularcan therefore come into contact with thin sections, sectioning waste,and/or paraffin sections. At least these functional regions of rotarymicrotome 1 are accordingly embodied, according to the presentinvention, in electrically conductive fashion, so that electrostaticcharging of, for example, section collection pan 5 with respect to theremaining assemblies of rotary microtome 1 is at least largelypreventable, since section collection pan 5 is in electricallyconductive contact with at least one further component of rotarymicrotome 1 that is likewise electrically conductive.

FIG. 2 is a perspective view showing section collection pan 5 of rotarymicrotome 1 of FIG. 1, in the removed state. Section collection pan 5 isembodied substantially in a U shape, and is made of plastic having thedesignation Antistatic-Equipped Grilamid LKN-5H, which can additionallybe equipped with a steel fiber braid (although this is not shown in FIG.2).

Although a rotary microtome is shown in FIGS. 1 and 2, let it be veryparticularly emphasized at this juncture that the present invention andthe embodiment of a microtome associated therewith can also encompass aslide microtome, a rotating disc microtome, or a vibratome.

In conclusion, be it noted very particularly that the exemplifyingembodiments discussed above serve merely to describe the teachingclaimed, but do not limit it to the exemplifying embodiments.

1. A microtome comprising a plurality of functional regions to beoperated manually, the plurality of functional regions including asample holder (2), a cutting device (3), section removal system (4), andsection collection pan (5); wherein at least one of the plurality offunctional regions of the microtome has an electrically conductivestructural element arranged for possible contact with paraffin sectionscut by the microtome, whereby electrostatic charging of the structuralelement is prevented.
 2. The microtome according to claim 1, wherein ahousing portion in the region of the cutting device (3) is anelectrically conductive structural element.
 3. The microtome accordingto claim 1, wherein a housing portion in the region of the sectionremoval system (4) is an electrically conductive structural element. 4.The microtome according to claim 1, wherein the section collection pan(5) is an electrically conductive structural element.
 5. The microtomeaccording to claim 1, wherein a housing portion in the region of thecutting device (3), a housing portion in the region of the sectionremoval system (4), and the section collection pan (5) are electricallyconductive structural elements.
 6. The microtome according to claim 2,wherein the housing portion in the region of the cutting device (3)comprises electrically conductive plastic.
 7. The microtome according toclaim 3, wherein the housing portion in the region of the sectionremoval system (4) comprises electrically conductive plastic.
 8. Themicrotome according to claim 4, wherein the section collection pan (5)comprises electrically conductive plastic.
 9. The microtome according toclaims 1, wherein the microtome includes housing portions made ofplastic comprising an electrically conductive addition.
 10. Themicrotome according to claim 9, wherein the electrically conductiveaddition to the plastic includes a metal mat.
 11. The microtomeaccording to claim 9, wherein the electrically conductive addition tothe plastic includes a steel fiber braid.
 12. The microtome according toclaim 9, wherein the electrically conductive addition to the plasticincludes a metal lattice.
 13. The microtome according to claim 9,wherein the electrically conductive addition to the plastic includesmetal fibers.
 14. The microtome according to claim 9, wherein theelectrically conductive addition to the plastic includes a metalliccoating.
 15. The microtome according to claim 5, wherein each of thehousing portions comprises a plastic having the designation Grilon BS ECor the designation Antistatic-Equipped Grilamid LKN-5H.
 16. Themicrotome according to claim 15, wherein the section collection pan (5)is made of metal.
 17. The microtome according to claim 15, wherein thesection collection pan (5) is made of stainless steel.
 18. The microtomeaccording to claim 1, further comprising an antistatic knife holder. 19.The microtome according to claim 1, further comprising means forelectrically connecting the electrically conductive structural elementstogether so that the electrically conductive structural elements can bebrought to a common electrical potential.
 20. The microtome according toclaim 19, wherein the means comprises an electrically conductive cable.21. The microtome according to claim 1, wherein the microtome isselected from a group consisting of a rotary microtome, a slidingmicrotome, and a rotating disc microtome.